[PATCH] Fix current stack unwinding when using DRASan

[Alexey Samsonov]

================
Comment at: asan_stack.h:51
@@ +50,3 @@
+        stack.Unwind(max_s, pc, bp, 0, 0, fast);                               \
+        stack.top_frame_bp = bp;                                               \
+      }                                                                        \
----------------
top_frame_bp should be already set by StackTrace::Unwind

================
Comment at: asan_stack.h:50
@@ +49,3 @@
+        /* If GetCurrentThread() has failed, try to do slow unwind anyways. */ \
+        stack.Unwind(max_s, pc, bp, 0, 0, fast);                               \
+        stack.top_frame_bp = bp;                                               \
----------------
If you're trying slow unwind, why not specify "false" instead of "fast" here?


http://llvm-reviews.chandlerc.com/D2290